The present invention relates to a wearing-part system which comprises a wearing-part holder and a wearing part.
Various types of devices for dredging, such as dredgers, bucket dredgers or other types of machines intended to excavate or otherwise work or move material or sediment, mainly under water, usually use teeth or another replaceable wearing part or tool mounted on the cutter head, the bucket or the apparatus that is used to work or move the material. For machinery designed to work the material or sediment using teeth, wear in most cases occurs on the teeth with which the machinery is equipped. The teeth are designed to be able to be replaced after they have become worn, and the teeth are designed to work or clear in different ways the material or sediment that is to be worked by the machinery.
A wearing part such as a tooth is mounted on the machinery, such as a cutter head on a dredger, for example by a screw joint or cotter joint. Various types of thermal assembly, such as welding or shrink-fitting, are other known assembly methods. The tooth can be mounted on a wearing-part holder or tool holder and replaced on a continuous basis. Forces acting on the wearing part, or the tool, affect the wearing-part holder and, after a considerable period of use, the wearing-part holder may also need to be changed. Traditionally, the wearing-part holder is welded to the cutter head or is mounted thereon using another thermal joining technique. However, it is also conceivable that the wearing-part holder is mounted using a screw joint, cotter joint or other mechanical method of assembly. It may also be that the tooth is mounted directly on the cutter head.
Patent document WO 2010/111015 A2 describes a locking system for locking a stabilized excavating tooth to an adapter. The patent document describes a mainly hollow excavating tooth designed with a first opening and a second opening, where the openings are designed in the walls of the excavating tooth, with the excavating tooth designed to surround an adapter with a cavity running through the adapter. When the excavating tooth is arranged on the adapter, an assembly hole is defined by the first opening of the excavating tooth, the adapter cavity and the second opening of the excavating tooth, through which a locking pin can be mounted. The locking pin is mounted through the first opening, through the adapter and into the second opening of the excavating tooth. The described excavating tooth is designed with two holes for mounting a locking pin, which means that the excavating tooth is sensitive to abrasive or other erosive or grinding influences from sediment of a grinding nature which, when working with the excavating tooth, will cause wear to the locking pin and the mounting holes.
U.S. Pat. No. 5,956,874 describes an excavating tooth arranged with a pocket which has an inner, an upper, a lower and two opposite side walls with two contact surfaces arranged mainly parallel to each other to prevent rotation of the excavating tooth around the holder of the excavating tooth. The described excavating tooth is designed with two holes for mounting a locking pin, which means that the excavating tooth is sensitive to abrasive, or other erosive or grinding influences from sediment of a grinding nature which, when working with the excavating tooth, will cause wear to the locking pin and the mounting holes.
Known teeth for dredging have been shown to be sensitive to working or dredging sediment of a grinding nature.
The invention intends to solve the above problems through the development of a tooth with an improved protection against wear from sediment, designed with an easily releasable lock to fix a tooth/wearing part to a wearing-part holder securely, simply and permanently.
It is desirable to provide the technical field with a wearing part having improved protection against wear from sediment, designed with improved retention, secured and/or fixed mounting or arrangement of a wearing part on a holder.
The invention relates, according to an aspect thereof, to a wearing-part holder, where the wearing-part holder comprises a first stop surface, which is arranged on the front portion of the wearing-part holder, a first contact surface and a second contact surface symmetrically arranged from a centre line L-L from the first stop surface of the wearing-part holder to a second stop surface and a third stop surface, where the second stop surface and the third stop surface are symmetrically arranged on each side of the centre line L-L from the first contact surface and the second contact surface to a third contact surface and a fourth contact surface, where the third contact surface and the fourth contact surface are symmetrically arranged on each side of the centre line L-L from the second stop surface and the third stop surface.
According to further aspects of the improved wearing-part holder, provision is made as follows:
the first contact surface and the second contact surface are symmetrically arranged from a centre line L-L, from the front portion of the wearing-part holder, at the first stop surface, extending to a position X, and where the second stop surface and the third stop surface are symmetrically arranged on each side of the centre line L-L, extending from position X to position Y, where position Y is at a longer distance in the longitudinal direction of the wearing-part holder, along the centre line L-L, from the front portion of the wearing-part holder compared to position X, and where the third contact surface and the fourth contact surface are symmetrically arranged on each side of the centre line L-L, extending from position Y to position Z, where position Z is at a longer distance in the longitudinal direction of the wearing-part holder, along the centre line L-L, from the front portion of the wearing-part holder compared to position Y;
a fifth contact surface is arranged at the tip of the wearing-part holder from the front portion of the wearing-part holder to a position V, where position V is arranged with a longer distance from the front portion of the wearing-part holder compared to position Z;
the wearing-part holder is arranged with a fourth stop surface, which is arranged along the centre line L-L from position X to position Y;
the wearing-part holder is arranged with a fifth stop surface, which is arranged from position V to position W where the fifth stop surface is arranged at right angles from the fifth contact surface;
the first contact surface, the second contact surface, the second stop surface, the third stop surface, the fourth stop surface, the third contact surface and the fourth contact surface are arranged on the opposite side of the wearing-part holder relative to the fifth contact surface;
the first stop surface, the first contact surface, the second contact surface, the second stop surface, the third stop surface, the fourth stop surface, the third contact surface, the fourth contact surface, the fifth contact surface and the fifth stop surface are bound together with clearance surfaces arranged between the stop surfaces and the contact surfaces.
The invention also relates to a wearing part arranged to fit a wearing-part holder, where the wearing part is arranged with an opening.
According to further aspects of the improved wearing part, provision is made as follows:
the wearing part is a tooth for dredging, where the wearing part covers a first section, a second section and a third section of the wearing-part holder.
The invention also relates to a wearing-part system comprising a wearing-part holder, a wearing part, and a lock.
According to further aspects of the improved wearing-part system, provision is made as follows:
a lock comprising a threaded rod is arranged on a catch, where an elastomer is arranged with a through-hole through which the threaded rod runs; a mounting nut which is arranged on the threaded rod, where a first washer is arranged between the elastomer and the mounting nut and a second washer is arranged between the elastomer and the wearing-part holder.